fixed bug in FindAllParallel;

don't display stop button again, if search is loaded from history

src/AddIns/Misc/SearchAndReplace/Project/Engine/SearchManager.cs

@@ -159,11 +159,10 @@ namespace SearchAndReplace
 					if (i >= taskCount) {
 						HandleResult(queue.Dequeue(), observer, exceptions, files);
 					}
-					if (exceptions.Count == 0) {
+					if (exceptions.Count > 0) break;
 					FileName file = files[i];
 					queue.Enqueue(System.Threading.Tasks.Task.Factory.StartNew(() => SearchFile(file)));
 				}
-				}
 				while (queue.Count > 0) {
 					HandleResult(queue.Dequeue(), observer, exceptions, files);
 				}

src/AddIns/Misc/SearchAndReplace/Project/Gui/DefaultSearchResult.cs

@@ -142,6 +142,7 @@ namespace SearchAndReplace
 	public class ObserverSearchResult : DefaultSearchResult, IObserver<SearchedFile>
 	{
 		Button stopButton;
+		bool finished;
 		
 		public ObserverSearchResult(string title)
 		{
@@ -164,18 +165,24 @@ namespace SearchAndReplace
 		{
 			var items = base.GetToolbarItems();
 			
+			if (!finished) {
 				stopButton = new Button { Content = new Image { Height = 16, Source = PresentationResourceService.GetBitmapSource("Icons.16x16.Debug.StopProcess") } };
 				stopButton.Click += StopButtonClick;
 				
 				items.Add(stopButton);
-			stopButton.Visibility = Visibility.Visible;
+			}
+			
 			return items;
 		}
 
 		void StopButtonClick(object sender, RoutedEventArgs e)
 		{
+			try {
 				stopButton.Visibility = Visibility.Hidden;
 				if (Registration != null) Registration.Dispose();
+			} finally {
+				finished = true;
+			}
 		}
 		
 		void IObserver<SearchedFile>.OnNext(SearchedFile value)
@@ -191,9 +198,13 @@ namespace SearchAndReplace
 		
 		void OnCompleted()
 		{
+			try {
 				stopButton.Visibility = Visibility.Collapsed;
 				if (Registration != null)
 					Registration.Dispose();
+			} finally {
+				finished = true;
+			}
 		}
 		
 		void IObserver<SearchedFile>.OnCompleted()